Refrigeration process



.larly to a refrigerant and the process of using the same whereby 1t is adapted for urrso STATES T iii ALBERT Gr. CRAWFORD, OF CHICAGO, ILLINOIS, ASSIGNOR T0 HALLEGK 'W. SEAMAN, 01? CLINTON, IOWA.

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Ito Drawing.

To all whom it may concern Be it known that T, ALBERT G. CRAWFORD, a citizen of the United States, and a resi dent of the city of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Refrigeration Process; and I do hereby declare that the following is a full, clear, and exact description of the same.

My invention has reference more particucommercial use in ice making, in cold stor age plants or for general refrigeration puroses. p The refrigerants now commonly used, such as ammonia gas, sulfur dioxid gas, and ethylchlorid, are objectionable for the reason that they are not only poisonous and corrosive to the pipes and receptacles in which they are used, but most of them as well as carbon dioxid, also require a high pressure and consequently a heavy installation in order to condense themvinto the liquid state.

It is an object of this invention, therefore, to provide a medium which may be utilized for carrying on the] process of refrigeration or ice making and which not only requires a lower pressure and consequently a lighter and less-expensive installation to utilize the same, but'which is also unaccompanied with the danger of poisoning and does not have the corrosive action on. the apparatus as the refrigerants heretofore used.

I have found that propylene of the formula C ll having a boiling point of -5 0 G, gives excellent results as a refrigerant. It is easily liquefiable under cold or pressure and does not decompose after being used for a long time in a refrigerating machine, and my experiments show that very low temperatures can be .obtained by using this material as a refrigerant.

The refrigerating process using propylene as the refrigerant is carried vout by using this refrigerant in a manner similar to that in which refrigerants have been used hereto- Specification of Letters Patent.

Application filed. May 27, 1918. Serial No. 236,870.

fore, except that it requires less pressure to condense and liquify than with some of the refrigerants heretofore employed, a lighter installation may be used and it is unnecessary to provide-precautions against cor-' rosion and poisonous gas as with refrigerants heretofore employed.

The propylene is introduced into a circulating system consisting of a compresser which applies pressureto the gas and re duces it to a liquid form, and the liquid, after being suitably cooled to dissipate the heat of compression, is led to and allowed tov evaporate in proximity to the material or compartment which is to be cooled, and as the evaporation takes place heat is absorbed thereby and a reduction in temperature takes place around the point at which the evaporation takes place. The gas resulting from the evaporation is then lead back to the compresser and again liquefied by pressure and a continuous circulation thereof is thereby maintained, the propylene being alternately compressed and liquefied and then expanded so as to continuously absorb heat and maintain the desired low temperature.

v I claim as my invention:

1. A refrigerating process which comprises compressing substantially pure propylene gase to liquefy the same, and evaporating the liquid by relieving the pressure thereon to extract heat from adjacent material. I

2. A refrigeration process which comprises compressing a non-acid gas having a hydrocarbon content consisting chiefly of propylene to liquefy the propylene, and evaporating the liquid by relieving the pres sure thereon to extract heat from adjacent materials.

In testimony whereof I have hereunto subscribed my name in the presence of two subscribing witnesses.

ALBERT G. CRAWFORD. Witnesses:

' LAWRENCE REIBSTEIN,

FRANK A. BREMER, Jr. 

